Downhole screen assembly

ABSTRACT

A screen assembly that is used with a well includes a base pipe, a screen and ribs. The base pipe has a non-perforated section and has a longitudinal axis. The screen at least partially circumscribes the non-perforated section of the base pipe, and the ribs extend longitudinally in an annular space between the screen and the non-perforated section. A flexible member (e.g., a wire) is wrapped around the ribs. Various other mechanisms may be used instead of the ribs and flexible member in the annular space. In this regard, such annular standoffs such as a corrugated material, a member that has longitudinal channels, and a member formed from a first set of wires that is interwoven with a second set of wires may be used. Alternatively, longitudinal channels may be formed in the outer surface of the base pipe.

BACKGROUND

The invention generally relates to a downhole screen assembly.

For purposes of filtering particulates from produced well fluid, a wellfluid production system may include sandscreen assemblies. Eachsandscreen assembly typically includes a screen (a wire wrap or a wovenwire mesh, as an example), which contains openings that are sized toallow the communication of well fluid into the interior space of theassembly while suppressing sand production. The interior space of thesandscreen assembly is in communication with production tubing.

SUMMARY

In an embodiment of the invention, a screen assembly that is used with awell includes base pipe, a screen and ribs. The base pipe has anon-perforated section and has a longitudinal axis. The screen at leastpartially circumscribes the non-perforated section of the base pipe, andthe ribs extend longitudinally in an annular space between the screenand the non-perforated section. A flexible member of the screen assemblyis wrapped around the ribs and is disposed in the annular space.

In another embodiment of the invention, a screen assembly that is usablewith a well includes a base pipe, a screen and a corrugated material.The screen at least partially circumscribes the base pipe, and thecorrugated material is located in an annular space between the screenand the base pipe.

In another embodiment of the invention, a screen assembly that is usablewith a well includes a base pipe, a screen, a first set of flexiblemembers and a second set of flexible members. The screen at leastpartially circumscribes the base pipe, and the first set of flexiblemembers extend longitudinally in an annular space between the screen andthe non-perforated section. The second set of flexible members isinterwoven with the first set of flexible members.

In another embodiment of the invention, a screen assembly that is usablewith a well includes a base pipe, and a screen. The base pipe has alongitudinal axis, and the screen at least partially circumscribes thebase pipe. One or more members of the screen assembly extendlongitudinally in an annular space between the screen and the base pipe.Each member includes a base portion and at least two side walls to format least one longitudinal channel.

In yet another embodiment of the invention, a screen assembly that isusable with a well includes a base pipe and a screen. The base pipe hasa longitudinal axis, and the screen at least partially circumscribes thebase pipe. Longitudinal channels are formed in the base pipe and are atleast partially circumscribed by the screen.

Advantages and other features of the invention will become apparent fromthe following drawing, description and claims.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a schematic diagram of a well according to an embodiment ofthe invention.

FIG. 2 is a schematic diagram of a screen assembly according to anembodiment of the invention.

FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 2according to embodiments of the invention.

FIG. 4 is a cross-sectional view of the screen assembly illustrating acorrugated material spacer of the assembly according to an embodiment ofthe invention.

FIG. 5 is a perspective view of a section of the screen assemblyillustrating a perforated and corrugated material used as an annularstandoff in the assembly according to an embodiment of the invention.

FIG. 6 is a perspective view of an alternative annular standoff createdusing woven metal wires according to an embodiment of the invention.

FIGS. 7, 8, 9 and 10 depict annular standoffs that are formed frommembers that have longitudinal channels according to differentembodiments of the invention.

FIG. 11 is a perspective view of a section of a base pipe of a screenassembly depicting axial grooves that are formed in the outer surface ofthe base pipe according to an embodiment of the invention.

DETAILED DESCRIPTION

Referring to FIG. 1, an embodiment 10 of a well (a subsea well or asubterranean well) in accordance with the invention includes a tubularstring 20 that is disposed inside a wellbore 24. Although the wellbore24 is depicted in FIG. 1 as being a vertical wellbore, the wellbore 24may be a deviated or a horizontal wellbore in accordance with otherembodiments of the invention. As depicted in FIG. 1, the tubular string20 traverses a particular production zone 30 of the well 10. Forpurposes of example, the production zone 30 is shown in FIG. 1 as beingformed between upper 32 and lower 36 annular isolation packers.

Inside the production zone 30, the tubular string 20 includes a seriesof connected sandscreen assemblies, each of which includes a sandscreensection 40 and an associated inflow control device 42. It is noted thatalthough one sandscreen section 40 and one inflow control device 42 aredepicted in FIG. 1, it is understood that the tubular string 20 and theproduction zone 30 in particular may include multiple inflow controldevices 42 and sandscreen sections 40, in accordance with embodiments ofthe invention.

The inflow control device 42, as it name implies, regulates the flow ofwell fluid from the annulus that immediately surrounds the associatedsandscreen section 40, through the sandscreen section 40 and into thecentral passageway of the tubular string 20. Thus, the tubular string 20has multiple inflow control devices 42, each of which is associated witha sandscreen section 40 and has an associated flow characteristic forpurposes of establishing a relatively uniform flow distribution from theproduction zone 30.

Various embodiments of the invention are set forth herein relating todifferent designs for the screen assembly. In particular, variousannular standoff designs for the screen assembly are described hereinfor purposes of forming an annular space between a filter (a woven wireor metal fiber filter) and a base pipe of the screen assembly. Theannular space receives well fluid that flows through the filter, and thewell fluid is communicated through radial perforations, or openings, inthe base pipe into the base pipe's central passageway. Depending on theparticular embodiment of the invention, the filter may or may notcircumscribe the portion of base pipe, which contains the openings.

FIG. 2 depicts a partial schematic view of the screen assembly 40 inaccordance with some embodiments of the invention. Although FIG. 2depicts a lefthand cross-sectional view of the screen assembly 40 alonga longitudinal axis 50, it is understood that the screen assembly 40 isgenerally symmetric about the longitudinal axis 50, with the depictionof the right hand side of the assembly being omitted from FIG. 2.

Referring to FIG. 2 in conjunction with the cross-section that isdepicted in FIG. 3, in general, the screen assembly 40 includes an innerbase pipe 60, which includes a non-perforated section 60 a, which iscircumscribed by a screen, or filter 100, such as a woven wire meshfilter or a metal fiber filter, depending on the particular embodimentof the invention. A perforated and tubular protective shroud 80surrounds the filter 100 about the longitudinal axis 50 and permitsfluid to be communicated through its perforations and pass through thefilter 100 into longitudinal passageways 121 (see cross-section of FIG.3), which are formed between longitudinally, or axially, extending wireribs 120. The ribs 120 may have many differential cross-sectional forms(round, rectangular, etc.), depending on the particular embodiment ofthe invention. The incoming fluid flow flows through these longitudinalpassageways 121 into an annular space 140, where the fluid is receivedin a perforated section 60 b of the base pipe 60. In this regard, in theperforated section 60 b, the base pipe 60 includes various nozzles,which contain specifically-sized orifices for purposes of regulating theflow into the screen assembly.

The longitudinally extending ribs 120 form a substantial part of theannular standoff between the base pipe 60 and the filter 100. Inaccordance with embodiments of the invention described herein, aspirally-wrapped flexible member, such as a wire 190, is concentric withthe longitudinal axis 50 extends around the longitudinal ribs 120 forpurposes of providing additional inner support for the filter 100. Thewire 190 may have many differential cross-sectional forms (round,rectangular, etc.), depending on the particular embodiment of theinvention. It is noted that, as depicted in FIGS. 2 and 3, thecross-sectional dimension of the wire 190 may be significantly smallerthan the cross-sectional dimension of each of the longitudinal ribs 120.Thus, the cross-sectional dimension of the longitudinal rib 120effectively establishes the radial standoff distance between the filter100 and the base pipe 60.

The gap between the wrapped wire 190 and the longitudinal ribs 120 issufficiently close such that the filter 100 under collapse conditionscannot deform into the annular flow area and reduce the annular flowarea.

Among the other features of the screen assembly 40, in accordance withsome embodiments of the invention, the screen assembly 40 includes anupper housing section 70, which is attached to the outer surface of thebase pipe 60 and provides support for the shroud 80 and the filter 100.In this regard, the filter 100 may be part of an assembly that includessolid sections 90 and 92. The screen assembly 40 may also include acover 160 that controls access to the annular space 150 and a middlehousing section 130 which provides lower support for the shroud 80 andsupport for the cover 160. The cover 160 is also supported by a lowerhousing section 180, that is attached to the outer surface of the basepipe 60.

Referring to FIG. 4, in another embodiment of the invention, the annularstandoff may be alternatively provided by a corrugated sheet material200, which is disposed in the annular region between the filter and thebase pipe 60. FIG. 4 depicts the outer protective shroud 80 with itbeing understood in that the filter 100 is disposed between the shroud80 and the corrugated material 200. As a more specific example, thecorrugated material 200 may be a metal, and the corrugated material 200may be perforated (see FIG. 5), for purposes of allowing fluid to flowthrough the corrugated material 200 and along the longitudinal axis 50of the base pipe 60 on the inner side of the corrugated material 200.

In other embodiments of the invention, the corrugated material 200 maybe solid and thus, may not be perforated in an arrangement in which thefluid flow is confined to the outside surface of the corrugated material200.

In accordance with other embodiments of the invention, an annularstandoff may be achieved using a wire mesh 220, which is depicted inFIG. 6. As shown, the wire mesh 220 includes a first set oflongitudinally, or axially, extending wires 230 (warp wire, forexample), which is interwoven with a second set of laterally extendingsmaller wires 240 (weft wire, for example).

Referring to FIGS. 7-10, the annular standoff may be created using railsthat contain axial channels on their outer or inner surfaces, dependingon the particular embodiment of the invention. More specifically, FIG. 7depicts longitudinally-extending members 250, each of which has acorresponding channel that faces the wire filter and faces away from thebase pipe 60. Each member 250 includes two side walls 254 and acorresponding base section 256. This arrangement creates a substantiallyU-shaped cross section, which is open, as indicated at reference numeral260. As depicted in FIG. 8, in some embodiments of the invention, thelongitudinal members 250 may be combined in a single, integrated member270, which contains multiple longitudinal channels 280. As shown in FIG.8, the multiple longitudinal channels 280 confine flow between themember 270 and the filter 100.

Referring to FIGS. 9 and 10, in accordance with some embodiments of theinvention, flow may be confined between the longitudinal member and theoutside surface of the base pipe 60. More specifically, FIG. 9 depictslongitudinally-extending members 300, which have U-shaped channels 302that are formed between a base portion of each of the members 300 andthe exterior surface of the base pipe 60. Perforations 304 are formed inthe members 300 for purposes of allowing fluid communication between thechannels and the filter 100. FIG. 10 depicts the integration, orconsolidation, of the members 300 into a single piece or integratedmember 320, which contains multiple longitudinal channels 324. Themember 320 includes a base plate 340, which includes perforations 330for purposes of establishing communication between the channels and thefilter 100.

As another variation, in accordance with other embodiments of theinvention, an annular standoff may be formed by longitudinal membersthat have axial channels on the outside (such as the longitudinalmembers 250 (FIG. 7) or 270 (FIG. 8)) in combination with a helicallywrapped flexible member (such as a wire) around these members, similarto the wire 190 (see also FIG. 2). This arrangement provides additionalsupport for the filter 100, thereby preventing deformation of the filter100 into the otherwise open channels under collapse conditions.

In yet another variation, FIG. 11 depicts a standoff that is created bycreating (milling, for example) longitudinal channels 360 in the outersurface of the base pipe 60 to provide the required flow area. Thefilter 100 is positioned directly over the channels 360. As analternative, an additional support layer may be disposed over thelongitudinal channels 360 and located between the outer surface of thebase pipe 60 and the filter 100. In this manner, this additional supportlayer may be constructed of, as example, woven mesh, welded square mesh,perforated sheet metal, helically wrapped wire, or any other supportlayer that prevents the mesh filter from deforming into the longitudinalchannels 360.

While the present invention has been described with respect to a limitednumber of embodiments, those skilled in the art, having the benefit ofthis disclosure, will appreciate numerous modifications and variationstherefrom. It is intended that the appended claims cover all suchmodifications and variations as fall within the true spirit and scope ofthis present invention.

1. A screen assembly usable with a well, comprising: a base pipe havinga non-perforated section and having a longitudinal axis; a screen atleast partially circumscribing the non-perforated section of the basepipe; ribs to extend longitudinally in an annular space between thescreen and the non-perforated section; and a flexible member to bewrapped around the ribs.
 2. The screen assembly of claim 1, wherein theflexible member comprises a wire.
 3. The screen assembly of claim 1,wherein the ribs comprise wires.
 4. The screen assembly of claim 3,wherein each wire has a cross-sectional dimension that is substantiallythe same as a distance between the non-perforated section of the basepipe and the screen.
 5. The screen assembly of claim 1, wherein theflexible member is spirally wrapped around the ribs.
 6. The screenassembly of claim 1, wherein the base pipe further comprises aperforated section not at least partially circumscribed by the screen,the perforated section to receive fluid communicated through the screen.7. A screen assembly usable with a well, comprising: a base pipe; ascreen at least partially circumscribing the base pipe; and a corrugatedmaterial located in an annular space between the screen and the basepipe.
 8. The screen assembly of claim 7, wherein the corrugated materialcomprises a metal.
 9. The screen assembly of claim 7, wherein thecorrugated material is perforated.
 10. A screen assembly usable with awell, comprising: a base pipe having a longitudinal axis; a screen atleast partially circumscribing the base pipe; a first set of flexiblemembers to extend longitudinally in an annular space between the screenand the base pipe; and a second set of flexible members interwoven withthe first set of flexible members.
 11. The screen assembly of claim 10,wherein the first set of flexible members comprise a first set of wires,the second set of flexible members comprise a second set of wires, andthe wires of the second set of wires each have a substantially smallercross-sectional dimension than wires of the first set of wires.
 12. Thescreen assembly of claim 10, wherein the first set of flexible memberscomprise a first set of wires, the second set of flexible memberscomprise a second set of wires, and the wires of the second set of wiresare substantially transverse to the wires of the first set of wires. 13.A screen assembly usable with a well, comprising: a base pipe having alongitudinal axis; a screen to at least partially circumscribing thebase pipe; and at least one member to extend longitudinally in anannular space between the screen and the base pipe, each membercomprising a base portion and at least two sidewalls to form at leastone longitudinal channel.
 14. The screen assembly of claim 13, whereinsaid at least one longitudinal channel comprises an open channel whichfaces the base pipe.
 15. The screen assembly of claim 13, wherein saidat least one longitudinal channel comprises an open channel which facesthe screen.
 16. The screen assembly of claim 15 further comprising: awire to be wrapped around the said at least one member.
 17. The screenassembly of claim 16, wherein the wire is adapted to be spirally wrappedaround said at least one member.
 18. The screen assembly of claim 13,wherein said at least one member is perforated.
 19. The screen assemblyof claim 13, wherein said at least one member forms multiplelongitudinal channels.
 20. A screen assembly usable with a well,comprising: a base pipe having a longitudinal axis; a screen to at leastpartially circumscribing the base pipe, wherein longitudinal channelsare formed in the base pipe and at least partially circumscribed by thescreen.
 21. The screen assembly of claim 20, further comprising: asupport layer to be located between the screen and the base pipe. 22.The screen assembly of claim 21, wherein the support layer comprises awoven mesh, a square mesh or a perforated sheet material.
 23. A methodusable with a well, comprising: providing a base pipe having anon-perforating section and having a longitudinal axis; at leastpartially surrounding a non-perforated section of the base pipe with ascreen; longitudinally extending ribs in an annular space between thescreen and the non-perforated section of the base pipe; and wrapping aflexible member around the ribs.
 24. The method of claim 23, wherein theribs comprise wires.
 25. The method of claim 23, wherein each wire has across-sectional dimension that is substantially the same as a distancebetween the non-perforated section of the base pipe and the screen. 26.The method of claim 23, wherein the flexible member comprises a wire.27. The method of claim 23, wherein the wire is spirally wrapped aroundthe ribs.
 28. The method of claim 23, wherein the base pipe furthercomprises a perforated section not at least partially circumscribed bythe screen, the perforated section to receive fluid communicated throughthe screen.
 29. A method usable with a well, comprising: providing abase pipe; at least partially surrounding the base pipe with a screen;and disposing a corrugated material in an annular space between thescreen and the base pipe.
 30. The method of claim 29, wherein thecorrugated material comprises a metal.
 31. The method of claim 29,wherein the corrugated material is perforated.
 32. A method usable witha well, comprising: providing a base pipe; at least partiallysurrounding the base pipe with a screen; extending a first set of wireslongitudinally in an annular space between the screen and the base pipe;and interweaving a second set of wires with the first set of wires. 33.The method of claim 32, wherein wires of the second set of wires eachhave a substantially smaller cross-sectional dimension than wires of thefirst set of wires.
 34. The method of claim 32, wherein wires of thesecond set of wires are substantially transverse to the wires of thefirst set of wires.
 35. A method usable with a well, comprising:providing a base pipe; at least partially surrounding the base pipe witha screen; extending at least one member longitudinally in an annularspace between the screen and the base pipe; and forming at least onelongitudinal channel in the member.
 36. The method of claim 35, whereinsaid at least one longitudinal channel comprises an open channel whichfaces the base pipe.
 37. The method of claim 35, wherein said at leastone longitudinal channel comprises an open channel which faces thescreen.
 38. The method of claim 37 further comprising: a wire to bewrapped around the said at least one member.
 39. The method of claim 37,wherein the wire is adapted to be spirally wrapped around said at leastone member.
 40. The method of claim 35, wherein said at least one memberis perforated.
 41. The method of claim 35, wherein said at least onemember forms multiple longitudinal channels.
 42. A method usable with awell, comprising: providing a base pipe; at least partially surroundingthe base pipe with a screen; and forming longitudinal channels in thebase pipe, the channels being at least partially circumscribed by thescreen.
 43. The method of claim 42, further comprising: disposing asupport layer between the screen and the base pipe.
 44. The method ofclaim 43, wherein the support layer comprises a woven mesh, a squaremesh or a perforated sheet material.